This application describes a four stage program to develop an Anthrax rPA vaccine with a significantly improved stability. An output from this program would be a vaccine candidate that when successfully licensed does not require refrigerated storage or supply chain, providing the government with a stockpile that is less costly to maintain and deploy. The vaccine would be more robust in terms of it's ability to withstand temperature extremes simplifying use in the field. The program also examines formulations that do not contain alhyrdrogel potentially yielding a safer product. The program studies lyophilization, micro-encapsulation, micro-particle crystallization and glassification in four stages designed to progress only those technologies showing a measurable improvement in stability without compromising potency in an animal challenge test and immunological response using surrogate markers. In stage 1 initial process development and optimization will be carried out using all technologies to produce formulations useable for accelerated stability trials in stage 2 and extensive previously developed Drug substance and Drug Product characterization tests and assays will be used to examine the effect of the technologies on the vaccine. In Stage 3 will develop one technology process to GMP pilot plant manufacture to produce material that will be used in stage 4 for toxicity. This data will then be used to design, cost and plan a non-clinical and clinical program to achieve license. Relevance This program targets the development of an anthrax vaccine with improved stability over currently available products. The successful completion of the program would yield an anthrax vaccine candidate that when licensed would reduce the costs of maintaining a National Stockpile. In addition, improved stability and robustness in use would greatly simplify the logistics for deploying the vaccine in an emergency yielding greater protection to the public.